Power consumption is a measure of performance of a processor. As consumer electronic devices such as laptops, desktops, net-books, e-books, smart-phones, PC tablets, and other smart devices, become popular and in high demand, battery life of these consumer electronic devices also becomes important. Manufacturers and designers of these consumer electronic devices routinely place these devices in “sleep modes” when the devices are inactive to save battery life and lower power consumption. The term “sleep mode” herein generally refers to operating a processor or device in lower power mode, in which the processor is not completely turned off but is operated at a power level to retain its memory content so that it may wake up for normal operation from the point it went into sleep mode.
However, in such “sleep modes,” the processors in the consumer devices continue to dissipate leakage power caused by inherent leakage current in transistors even when the transistors are off. Leakage current is also referred to as sub-threshold current. Efforts to minimize leakage include the use of strained silicon, high-k dielectrics, and/or stronger dopant levels in the semiconductor. However, such efforts are process technology related efforts.